History of Technology in India, Vol. I: From Antiquity to c. 1200 A.D. v1.c20.3

v1.c20.3

Reason for dye activity among dyes is found in their basic or acidic substituents. It is easy to dye wool or silk because they are essentially protein and have both basic and acidic properties. But dyeing cotton is difficult without the prior use of mordants which are substances found to be capable of penetrating and adhering to the fibres. The dye added after using mordants forms an insoluble product in the cotton fibres.